全文获取类型
收费全文 | 21891篇 |
免费 | 2159篇 |
国内免费 | 21篇 |
出版年
2023年 | 109篇 |
2022年 | 226篇 |
2021年 | 493篇 |
2020年 | 221篇 |
2019年 | 322篇 |
2018年 | 374篇 |
2017年 | 322篇 |
2016年 | 598篇 |
2015年 | 1047篇 |
2014年 | 1140篇 |
2013年 | 1329篇 |
2012年 | 1770篇 |
2011年 | 1736篇 |
2010年 | 1137篇 |
2009年 | 916篇 |
2008年 | 1436篇 |
2007年 | 1387篇 |
2006年 | 1260篇 |
2005年 | 1248篇 |
2004年 | 1206篇 |
2003年 | 1119篇 |
2002年 | 1069篇 |
2001年 | 222篇 |
2000年 | 143篇 |
1999年 | 232篇 |
1998年 | 272篇 |
1997年 | 179篇 |
1996年 | 148篇 |
1995年 | 142篇 |
1994年 | 128篇 |
1993年 | 124篇 |
1992年 | 122篇 |
1991年 | 118篇 |
1990年 | 116篇 |
1989年 | 96篇 |
1988年 | 77篇 |
1987年 | 80篇 |
1986年 | 64篇 |
1985年 | 93篇 |
1984年 | 84篇 |
1983年 | 79篇 |
1982年 | 92篇 |
1981年 | 89篇 |
1980年 | 88篇 |
1979年 | 43篇 |
1978年 | 71篇 |
1977年 | 51篇 |
1976年 | 44篇 |
1975年 | 56篇 |
1974年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
Kathleen M. Gorman Esther Meyer Detelina Grozeva Egidio Spinelli Amy McTague Alba Sanchis-Juan Keren J. Carss Emily Bryant Adi Reich Amy L. Schneider Ronit M. Pressler Michael A. Simpson Geoff D. Debelle Evangeline Wassmer Jenny Morton Diana Sieciechowicz Eric Jan-Kamsteeg Alex R. Paciorkowski Manju A. Kurian 《American journal of human genetics》2019,104(5):948-956
994.
Caymen M. Novak Eric N. Horst Charles C. Taylor Catherine Z. Liu Geeta Mehta 《Biotechnology and bioengineering》2019,116(11):3084-3097
Breast cancer cells experience a range of shear stresses in the tumor microenvironment (TME). However most current in vitro three-dimensional (3D) models fail to systematically probe the effects of this biophysical stimuli on cancer cell metastasis, proliferation, and chemoresistance. To investigate the roles of shear stress within the mammary and lung pleural effusion TME, a bioreactor capable of applying shear stress to cells within a 3D extracellular matrix was designed and characterized. Breast cancer cells were encapsulated within an interpenetrating network hydrogel and subjected to shear stress of 5.4 dynes cm−2 for 72 hr. Finite element modeling assessed shear stress profiles within the bioreactor. Cells exposed to shear stress had significantly higher cellular area and significantly lower circularity, indicating a motile phenotype. Stimulated cells were more proliferative than static controls and showed higher rates of chemoresistance to the anti-neoplastic drug paclitaxel. Fluid shear stress-induced significant upregulation of the PLAU gene and elevated urokinase activity was confirmed through zymography and activity assay. Overall, these results indicate that pulsatile shear stress promotes breast cancer cell proliferation, invasive potential, chemoresistance, and PLAU signaling. 相似文献
995.
Anne Mouré Elodie Bacou Steffi Bosch Dominique Jegou Apolline Salama David Riochet Olivier Gauthier Gilles Blancho Jean-Paul Soulillou Denis Poncelet Eric Olmos Jean-Marie Bach Mathilde Mosser 《Biotechnology and bioengineering》2019,116(5):1176-1189
The bioartificial pancreas encapsulating pancreatic islets in immunoprotective hydrogel is a promising therapy for Type 1 diabetes. As pancreatic islets are highly metabolically active and exquisitely sensitive to hypoxia, maintaining O2 supply after transplantation remains a major challenge. In this study, we address the O2 limitation by combining silicone-encapsulated CaO2 (silicone-CaO2) to generate O2 with an extracellular hemoglobin O2-carrier coencapsulated with islets. We showed that the hemoglobin improved by 37% the O2-diffusivity through an alginate hydrogel and displayed antioxidant properties neutralizing deleterious reactive O2 species produced by silicone-CaO2. While the hemoglobin alone failed to maintain alginate macroencapsulated neonate pig islets under hypoxia, silicone-CaO2 alone or combined to the hemoglobin restored islet viability and insulin secretion and prevented proinflammatory metabolism (PTGS2 expression). Interestingly, the combination took the advantages of the two individual strategies, improved neonate pig islet viability and insulin secretion in normoxia, and VEGF secretion and PDK1 normalization in hypoxia. Moreover, we confirmed the specific benefits of the combination compared to silicone-CaO2 alone on murine pseudo-islet viability in normoxia and hypoxia. For the first time, our results show the interest of combining an O2 provider with hemoglobin as an effective strategy to overcome O2 limitations in tissue engineering. 相似文献
996.
997.
998.
999.
1000.